A rescue or emergency cerclage is placed in women whose cervix is already dilated. This procedure should be considered when the cervix is dilated more than 1 to 2 cm with no perceived uterine contractions. It’s also important to note that the patient shouldn’t have evidence of chorioamnionitis (the inflammation of fetal membranes).
Small randomized clinical trials have shown that emergency cerclages can prolong pregnancies by four weeks. Other observational students have reported emergency cerclages to prolong pregnancy by six to nine weeks.